Identification of the main pollutants and sources has important practical significance for the control and management of water quality in Guiyang's surrounding river areas. Based on the continuous field observation of the experiment from July,2010 to April,2011,this paper studies the concentration of nitrogen and phosphorus loss characteristics of Maixi river watershed,which is near to Guiyang's important water source-Baihua Lake reservoir,so as to provide a reference for Guiyang suburban small watershed so...